Can we pause and resume download in news stand as we do it in nsurlconnection setting range for NSMutablerequest ??
I tried to set the range for the NSMutablerequest for the NKAssetDownload.
But it will start downloading from the beginning....
NSMutableURLRequest *urlReq=[[NSMutableURLRequest alloc]initWithURL:[NSURL URLWithString:downloadURl]];
int totalLength=[[[NSUserDefaults standardUserDefaults] valueForKey:#"TotalLength"] intValue];
int recievedLength=[[[NSUserDefaults standardUserDefaults] valueForKey:#"Recieved"] intValue];
[urlReq setValue:[NSString stringWithFormat:#"bytes=%d-%d",recievedLength,totalLength] forHTTPHeaderField:#"Range"];
NKAssetDownload *mAssetDownload = [mIssue addAssetWithRequest:urlReq];
But download begins from first and not from the range.
Related
My app needs to track the users location in the background but it is failing to send a 'get' request. The http request gets sent immediately when the app comes to the foreground. I am using RestKit for all my network requests and I followed this tutorial to setup my background locations service.
In my applicationDidEnterBackground
-(void)applicationDidEnterBackground:(UIApplication *)application
{
self.bgLocationManager = [[CLLocationManager alloc] init];
self.bgLocationManager.delegate = self;
[self.bgLocationManager startMonitoringSignificantLocationChanges];
NSLog(#"Entered Background");
}
and I stopMonitoringSignificantLocationChange in my applicationDidBecomeActive delegate
This is my locationManager delegate where I accept the new updated location and send to my server
-(void) locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation
fromLocation:(CLLocation *)oldLocation
{
NSLog(#"I am in the background");
bgTask = [[UIApplication sharedApplication]
beginBackgroundTaskWithExpirationHandler:
^{
[[UIApplication sharedApplication] endBackgroundTask:bgTask];
}];
// ANY CODE WE PUT HERE IS OUR BACKGROUND TASK
NSString *currentLatitude = [[NSString alloc]
initWithFormat:#"%g",
newLocation.coordinate.latitude];
NSString *currentLongitude = [[NSString alloc]
initWithFormat:#"%g",
newLocation.coordinate.longitude];
NSString *webToken = [[NSUserDefaults standardUserDefaults] stringForKey:#"userWebToken"];
NSLog(#"I am in the bgTask, my lat %#", currentLatitude);
NSDictionary *queryParams;
queryParams = [NSDictionary dictionaryWithObjectsAndKeys:webToken, #"auth_token", currentLongitude, #"lng", currentLatitude, #"lat", nil];
RKRequest* request = [[RKClient sharedClient] post:#"/api/locations/background_update" params:queryParams delegate:self];
//default is RKRequestBackgroundPolicyNone
request.backgroundPolicy = RKRequestBackgroundPolicyContinue;
// AFTER ALL THE UPDATES, close the task
if (bgTask != UIBackgroundTaskInvalid)
{
[[UIApplication sharedApplication] endBackgroundTask:bgTask];
bgTask = UIBackgroundTaskInvalid;
}
}
The network requests works as planned but it will not get called in the background. Is there any additional steps I need? In my info.plist I have the Required Background modes key and location-services as the value.
EDIT
I also referred to this past SO answer. I ran some tests with putting logs throughout the didUpdateToLocation call and they were all called but the 'get' request was not sent. Instead when I finally launch the app to the foreground it sent all the built of network requests (over 10).
EDIT (2)
I added RKRequestBackgroundPolicyContinue to my request but it did not change my results. (As you can see here in the background upload/download for restkit). I see Restkit initialize the host but fails to send the request until the app becomes active.
ANSWER
RestKit must be doing something that is prohibited in the background. Using an NSURLRequest works perfectly.
NSMutableURLRequest * urlRequest = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:#"http://www.example.com/api/locations/background_update"]];
[urlRequest setValue:#"application/json" forHTTPHeaderField:#"Accept"];
[urlRequest setValue:#"application/json" forHTTPHeaderField:#"Content-Type"];
[urlRequest setHTTPMethod:#"POST"];
[urlRequest setHTTPBody:jsonData];
NSHTTPURLResponse *response = nil;
[NSURLConnection sendSynchronousRequest:urlRequest
returningResponse:&response
error:&error];
It is fine to use a synchronous request since there is no UI to disrupt with background tasks
Re-creating original suggestion as an answer
Have your try replacing your restKit calls with a stock synchronous NSURLConnection? – dklt Sep 20
I'm using exactly the same code as you and it works for me in RestKit. The only way I could make it work is ny creating a synchronous request (it doesn't make a lot of sense to do it asynchronously in this context anyway!). Please check this code and let us know if it works:
// REMEMBER. We are running in the background if this is being executed.
// We can't assume normal network access.
// bgTask is defined as an instance variable of type UIBackgroundTaskIdentifier
// Note that the expiration handler block simply ends the task. It is important that we always
// end tasks that we have started.
_bgTask = [[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:
^{
[[UIApplication sharedApplication] endBackgroundTask:_bgTask];
}];
// ANY CODE WE PUT HERE IS OUR BACKGROUND TASK
// For example, I can do a series of SYNCHRONOUS network methods (we're in the background, there is
// no UI to block so synchronous is the correct approach here).
NSNumber *latNumber = [NSNumber numberWithDouble:location.coordinate.latitude];
NSNumber *lngNumber = [NSNumber numberWithDouble:location.coordinate.longitude];
NSNumber *accuracyNumber = [NSNumber numberWithDouble:location.horizontalAccuracy];
NSDictionary *params = [NSDictionary dictionaryWithKeysAndObjects:#"lat",latNumber,#"lng",lngNumber,#"accuracy",accuracyNumber, nil];
RKURL *URL = [RKURL URLWithBaseURL:[NSURL URLWithString:SERVER_URL] resourcePath:#"/user/location/update" queryParameters:params];
RKRequest *request = [RKRequest requestWithURL:URL];
request.method = RKRequestMethodGET;
NSLog(#"Sending location to the server");
RKResponse *response = [request sendSynchronously];
if (response.isFailure)
NSLog(#"Unable to send background location, failure: %#", response.failureErrorDescription);
else {
NSError *error = nil;
NSDictionary *parsedBody = [response parsedBody:&error];
if (YES == [[parsedBody objectForKey:#"result"] boolValue]){
NSLog(#"Background location sent to server");
}
else {
//Something went bad
NSLog(#"Failed to send background location");
}
}
// AFTER ALL THE UPDATES, close the task
if (_bgTask != UIBackgroundTaskInvalid)
{
[[UIApplication sharedApplication] endBackgroundTask:_bgTask];
_bgTask = UIBackgroundTaskInvalid;
}
I'm almost sure the new thread spawned for your RKClient request is automatically killed after invoking it.
When you're application is running in the background you can finish a HTTP request you started before you entered the background but you cannot initiate a new request. You can only initiate certain network operations while in the background (voip, newsstand).
I'm successfully making a ASIFormDataRequest using the below code.
//get groups
if (![self queue]) {
[self setQueue:[[[NSOperationQueue alloc] init] autorelease]];
}
//make the url by appending the URL from the Constant class to the jsp name
NSURL *url = [NSURL URLWithString:[NSString stringWithFormat:#"%#/%#", URL, #"connectors/searchGroupsServlet.jsp"]];
ASIFormDataRequest *request = [ASIFormDataRequest requestWithURL:url];
[request addRequestHeader:#"User-Agent" value:USER_AGENT];
[request addPostValue:[login username] forKey:#"username"];
[request addPostValue:[login password] forKey:#"password"];
[request addPostValue:[searchText lowercaseString] forKey:#"query"];
[request addPostValue:GROUP_FILTER_LIMIT forKey:#"limit"];
[request setDelegate:self];
[request setDidFinishSelector:#selector(requestDone:)];
[request setDidFailSelector:#selector(requestWentWrong:)];
This request is currently made on every key press a user makes in a searchbox (The text typed is sent off in the request as the search string). However, rather than sending the request on every key press, I want to delay the request by a second to allow users to type further characters into the searchbox before the request is sent.
I've successfully made a thread that waits a second as users continue to type (although admittedly Im not convinced this is the best way to do it yet, but it works for now)...
this
[self performSelectorInBackground:#selector(wait:) withObject:request];
calls this
-(void)wait:(NSString *)request
{
[NSThread sleepForTimeInterval:1.00];
[[self queue] addOperation:request]; //queue is an NSOperationQueue
}
but, if a user continues to type, I haven't managed to work out how to cancel the request or not put the request in the queue, or empty the queue and replace it with the new request.
Finally, obviously I could force users to wait until they have pressed the 'search' button on the pop-up keyboard, but I was hoping to provide search results without that.
Thanks
The answer was to create an NSTimer, and invalidate it whenever a new key press had been made. Then start it again.
[timer invalidate];
You can try this to cancel
+ (void)cancelPreviousPerformRequestsWithTarget:(id)aTarget selector:(SEL)aSelector object:(id)anArgument
This may sounds weird but please bear with me. I have 6-7 API calls which make request to a server one by one. I want to implement these calls in a separate thread. But when I do this, none of my delegate methods (of NSURLConnection) gets called even after managing a separate NSRunloop
([[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode beforeDate:[NSDate distantFuture]];)
Can anyone suggests me alternative approach for the same or any correction in existing functionality??
Use ASIHTTPRequest instead. It's much easier to use than NSURLConnection.
a quick google threw up this: http://blog.emmerinc.be/index.php/2009/03/15/multiple-async-nsurlconnections-example/ he is using a dictionary to manage multiple requests
Using a separate thread for each NSURLConnection, which is already multithreaded is a bad idea. It's just pointlessly using system resources and defeating NSURLConnections attempts to manage connections optimally. However, it does work so if you are not receiving delegate messages you are doing something wrong. Rather than find an alternative way todo it you should try to get to the bottom of your problem with the runloop.
I'm using ASIHTTPRequest to do the similar operation. Go through the following code change the downloadAllIcons method to suit your requirement,
[NSThread detachNewThreadSelector:#selector(downloadAllIcons:) toTarget:self withObject:xmlData];
-(void) downloadAllIcons:(NSData *)_xmlData
{
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
NSArray *IconList= PerformXMLXPathQuery(_xmlData,#"//icon");
[[NSUserDefaults standardUserDefaults] setObject:IconList forKey:#"IconList"];
for (int i=0; i<[IconList count]; i++) {
if ([[NSUserDefaults standardUserDefaults] objectForKey:[[IconList objectAtIndex:i] objectForKey:#"nodeContent"]]==nil) {
NSData * responseData=[self downloadProccessedImage:[[IconList objectAtIndex:i] objectForKey:#"nodeContent"]];
if(responseData)
[[NSUserDefaults standardUserDefaults] setObject:responseData forKey:[[IconList objectAtIndex:i] objectForKey:#"nodeContent"]];
//NSLog(#"%#",[[IconList objectAtIndex:i] objectForKey:#"nodeContent"]);
}
}
[pool release];
}
-(id) downloadProccessedImage:(NSString *)_URL
{
NSData *response=nil;
NSURL *url = [NSURL URLWithString:_URL];
ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url];
[request setTimeOutSeconds:60];
[ASIHTTPRequest setShouldThrottleBandwidthForWWAN:YES];
[request startSynchronous];
NSError *error = [request error];
if (!error)
{
response = [request responseData];
}
return response;
}
Hey! I need to know how I can have my iOS Application start a download in the background of the application (like, have the download run in the AppDelegate file) so changing ViewControllers will not interrupt or cancel the download. I also need to be able to get the progress of the download (0.00000 - 1.00000), to set a UIProgressView object to, which also means I need a - (void)progressDidChangeTo:(int)progress function.
Just use ASIHTTPRequest it is way easier than NSURLRequest and does exactly what you need.
It examples that shows how to download in background and how to report progress.
I wouldn't download anything in the AppDelegate directly. Instead I would create a separated class just for that purpose. Let's call it MyService I would then initialize that class in my app delegate.
The class can work as a singleton or can be passed to each view controller that requires it.
In MyService class I would add the ASINetworkQueue and few methods to handle the requests when they are ready. Here is the code from ASI examples that you can use:
- (IBAction)startBackgroundDownloading:(id)sender
{
if (!self.queue) {
self.queue = [[[ASINetworkQueue alloc] init] autorelease];
}
NSURL *url = [NSURL URLWithString:#"http://allseeing-i.com"];
ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url];
[request setDelegate:self];
[request setDidFinishSelector:#selector(requestDone:)];
[request setDidFailSelector:#selector(requestWentWrong:)];
[self.queue addOperation:request]; //queue is an NSOperationQueue
[self.queue go];
}
- (void)requestDone:(ASIHTTPRequest *)request
{
NSString *response = [request responseString];
//Do something useful with the content of that request.
}
- (void)requestWentWrong:(ASIHTTPRequest *)request
{
NSError *error = [request error];
}
If you need to set the progress bar. I would just expose the setDownloadProgressDelegate of ASINetworkQueue in my MyService class and set it in my ViewControllers like that:
[[MyService service] setDownloadProgressDelegate: self.myUIProgressView];
BTW. If you need to continue downloading even when your app exits you can set ShouldContinueWhenAppEntersBackground property of your request to YES.
you can use NSURLConnection to start an asynchronous request that won't cause your UI to be frozen. You can do it by doing something like:
NSURLRequest *urlRequest = [[NSURLRequest alloc] initWithURL:url];
connection = [[NSURLConnection alloc] initWithRequest:urlRequest delegate:self];
[urlRequest release];
in order to have your progress you can use the:
connection:didReceiveResponse:(NSURLResponse *)response;
delegate call to inspect the response.expectedContentLength and then use the
connection:didReceiveData:(NSData *)data
to track the amount of data that was downloaded and calculate a percentage.
Hope this helps,
Moszi
I've queried this forum for hours looking for an idea/answer/solution for my problem, but came up empty every time.
i have created a SynchronousRequest using the following:
NSMutableURLRequest *theRequest = [[NSMutableURLRequest alloc] initWithURL:url];
NSString *msgLength = [NSString stringWithFormat:#"%d", [params length]];
[theRequest addValue: msgLength forHTTPHeaderField:#"Content-Length"];
[theRequest setHTTPMethod:#"POST"];
[theRequest setTimeoutInterval:3.0];
[theRequest setCachePolicy:NSURLRequestReturnCacheDataElseLoad];
[theRequest setHTTPBody: [params dataUsingEncoding:NSUTF8StringEncoding]];
NSData *aData = [NSURLConnection sendSynchronousRequest:theRequest returningResponse:&response error:&error];
the connection is established, and the data is retrieved successfully to aData.
but, when there is a connection problem, or the server is not available, the request is attempting to connect for 75 seconds which is tooooo much time for the timeout interval,
i have added the setTimeoutInterval parameter (with 3 seconds) but it does not affect the connection,
i saw some answers from people saying that i should use NSTimer, and runLoop,
but it's not clear to me how this should be implemented.
PLEASE HELP!
the users are waiting 75 seconds before they get a timeout error message! it's ridiculous
appreciate your help.
On the iPhone a minimum timeout interval is hard-coded into the framework, you can't set the timeout below 75 seconds. Apple did this because there's frequently a significant amount of lag when you're dealing with cellular data connections.
What you want to do in most situations use an asynchronous network connection (so that your GUI doesn't freeze) and allow the request to go the full 75 seconds before timing out.
Read Apple's instructions for how to set up an asynchronous connection, it's a great start.
If you really do want to set a very short timeout, you can use an NSTimer like this:
- (void)loadURL:(NSURL *)url {
/* Set up the NSURLConnection here */
[NSTimer scheduledTimerWithTimeInterval:3.0 target:self selector:#selector(cancelURLConnection:) userInfo:nil repeats:NO];
}
- (void)cancelURLConnection:(NSTimer)timer {
[self.connection cancel]
}
I'm not at my desktop, so that code may be buggy and it's definitely incomplete. Also note that you can't easily use a timer to kill a synchronous web requset, since the synchronous request blocks the runloop and the timer won't fire until the request is done.
may I suggest having a look at the sample code from simpleURLconnections?
From that code, the NSMutableURLRequest is sent using
self.connection = [NSURLConnection connectionWithRequest:request delegate:self];
for both retrieving and sending data (but have a look at the rest of the code). Maybe the problem lies in the sendSynchronousRequest and you can avoid using that ?
Regards
You could use some code like the following (taken from an app I'm working on) - isFinished is a global variable:
- (void)someMethod {
[[WSXMLRPCController sharedInstance] validateLicenseWithServiceURL:serviceUrl username:username password:password delegate:self];
isFinished = NO;
NSDate *endDate = [NSDate dateWithTimeIntervalSinceNow:10]; // break the loop after 10 seconds and not finished with the request from the call above ...
while(!isFinished && [[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode beforeDate:endDate]){
if([endDate compare:[NSDate date]] == NSOrderedAscending){
[self connection:nil didFailWithError:nil forMethod:nil];
}
}
}
- (void)connection: (XMLRPCConnection *)connection didFailWithError: (NSError *)error forMethod: (NSString *)method {
isFinished = YES;
}
- (void)connection: (XMLRPCConnection *)connection didReceiveResponse: (XMLRPCResponse *)response forMethod: (NSString *)method {
isFinished = YES;
}
Probably not the cleanest solution, but it works. BTW this code is making use of the WordPress XMLRPCConnection class and delegate methods, but the same if possible with the NSURLConnection class and delegate methods.